import React, { Component } from 'react'

export default class Demo extends Component {
  state = {count:0}

  add = ()=>{
    //对象式的setState
    //1.获取原来的count值
    // const {count} = this.state
    //2.更新状态
    // this.setState({count:count+1}, ()=>{
    //   console.log(this.state.count)
    // })


    this.setState(state=>({count:state.count+1}))
  }
  render() {
    return (
      <div>
        <h1>当前求和为：{this.state.count}</h1>  
        <button onClick={this.add}>点我+1</button>
      </div>
    )
  }
}
